An immunohistochemical study of the pancreatic endocrine cells of the Korean golden frog, Rana plancyi chosenica

Abstract

The regional distribution and quantitative frequency of pancreatic endocrine cells were demonstrated in the Korean golden frog (Rana plancyi chosenica Okada), which is known as a Korean endemic species, for the first time, by immunohistochemical methods using specific mammalian antisera to insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). In the pancreas of the Korean golden frog, all four endocrine cell types were demonstrated. Insulin- and glucagon-positive cells were located in the pancreas as single cells or islet-like clusters with frequencies of 85.90±18.28 and 54.30±8.77/1,000/1,000 cells, respectively. Somatostatin-containing cells were also dispersed in the pancreas as single cells or clusters but in the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cell clusters. Cells stained for somatostatin cell frequency was 15.50±3.10/1000 cells. PP-containing cells were also distributed as single cells or clusters with frequency of 53.40±11.96/1,000 cells. Clusters consisted of PP-positive cells are distributed as a core type and a marginally distributed type. Overall, there were 40.84±3.81% insulin-, 26.02±1.71% glucagon-, 7.63±2.09% somatostatin- and 25.51±3.26% PP-IR cells.

Figure 1

Cells stained for insulin were distributed as single cells (A) or clusters (A, B) in the pancreas of the Korean golden frog. Scale bars: 80 µm; PAP method.

Figure 2

Cells stained for glucagon were located as single cells (A) or clusters (B) in the pancreas of the Korean golden frog. Scale bars: 80 µm; PAP method.

Figure 3

Cells stained for somatostatin were dispersed as single cells (A) or clusters (B, C) in the pancreas of the Korean golden frog. In the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cells (B, C). Scale bars: 80 µm; PAP method.

Figure 4

Cells stained for PP were dispersed as solitary cells (A, B) or clusters (B, C) in the pancreas of the Korean golden frog. Clusters are distributed as a core type (B) and a marginally distributed type (C). Scale bars: 80 µm; PAP method.